From 984cfe4e252681d516df056b982e3c47b66fba92 Mon Sep 17 00:00:00 2001 From: Jason Gunthorpe Date: Wed, 18 Dec 2019 13:40:35 -0400 Subject: mm/mmu_notifier: Rename struct mmu_notifier_mm to mmu_notifier_subscriptions The name mmu_notifier_mm implies that the thing is a mm_struct pointer, and is difficult to abbreviate. The struct is actually holding the interval tree and hlist containing the notifiers subscribed to a mm. Use 'subscriptions' as the variable name for this struct instead of the really terrible and misleading 'mmn_mm'. Signed-off-by: Jason Gunthorpe --- include/linux/mm_types.h | 2 +- include/linux/mmu_notifier.h | 18 +++++++++--------- 2 files changed, 10 insertions(+), 10 deletions(-) (limited to 'include/linux') diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h index 270aa8fd2800..e87bb864bdb2 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -490,7 +490,7 @@ struct mm_struct { /* store ref to file /proc//exe symlink points to */ struct file __rcu *exe_file; #ifdef CONFIG_MMU_NOTIFIER - struct mmu_notifier_mm *mmu_notifier_mm; + struct mmu_notifier_subscriptions *notifier_subscriptions; #endif #if defined(CONFIG_TRANSPARENT_HUGEPAGE) && !USE_SPLIT_PMD_PTLOCKS pgtable_t pmd_huge_pte; /* protected by page_table_lock */ diff --git a/include/linux/mmu_notifier.h b/include/linux/mmu_notifier.h index 9e6caa8ecd19..a302925fbc61 100644 --- a/include/linux/mmu_notifier.h +++ b/include/linux/mmu_notifier.h @@ -8,7 +8,7 @@ #include #include -struct mmu_notifier_mm; +struct mmu_notifier_subscriptions; struct mmu_notifier; struct mmu_notifier_range; struct mmu_interval_notifier; @@ -265,7 +265,7 @@ struct mmu_notifier_range { static inline int mm_has_notifiers(struct mm_struct *mm) { - return unlikely(mm->mmu_notifier_mm); + return unlikely(mm->notifier_subscriptions); } struct mmu_notifier *mmu_notifier_get_locked(const struct mmu_notifier_ops *ops, @@ -364,7 +364,7 @@ static inline bool mmu_interval_check_retry(struct mmu_interval_notifier *mni, return READ_ONCE(mni->invalidate_seq) != seq; } -extern void __mmu_notifier_mm_destroy(struct mm_struct *mm); +extern void __mmu_notifier_subscriptions_destroy(struct mm_struct *mm); extern void __mmu_notifier_release(struct mm_struct *mm); extern int __mmu_notifier_clear_flush_young(struct mm_struct *mm, unsigned long start, @@ -480,15 +480,15 @@ static inline void mmu_notifier_invalidate_range(struct mm_struct *mm, __mmu_notifier_invalidate_range(mm, start, end); } -static inline void mmu_notifier_mm_init(struct mm_struct *mm) +static inline void mmu_notifier_subscriptions_init(struct mm_struct *mm) { - mm->mmu_notifier_mm = NULL; + mm->notifier_subscriptions = NULL; } -static inline void mmu_notifier_mm_destroy(struct mm_struct *mm) +static inline void mmu_notifier_subscriptions_destroy(struct mm_struct *mm) { if (mm_has_notifiers(mm)) - __mmu_notifier_mm_destroy(mm); + __mmu_notifier_subscriptions_destroy(mm); } @@ -692,11 +692,11 @@ static inline void mmu_notifier_invalidate_range(struct mm_struct *mm, { } -static inline void mmu_notifier_mm_init(struct mm_struct *mm) +static inline void mmu_notifier_subscriptions_init(struct mm_struct *mm) { } -static inline void mmu_notifier_mm_destroy(struct mm_struct *mm) +static inline void mmu_notifier_subscriptions_destroy(struct mm_struct *mm) { } -- cgit v1.2.3-71-gd317 From 1991722a70ffb1f0199a5690a31a5c7822007b1f Mon Sep 17 00:00:00 2001 From: Jason Gunthorpe Date: Tue, 14 Jan 2020 11:11:17 -0400 Subject: mm/mmu_notifiers: Use 'subscription' as the variable name for mmu_notifier The 'subscription' is placed on the 'notifier_subscriptions' list. This eliminates the poor name 'mn' for this variable. Signed-off-by: Jason Gunthorpe --- include/linux/mmu_notifier.h | 30 +++---- mm/mmu_notifier.c | 183 ++++++++++++++++++++++++------------------- 2 files changed, 117 insertions(+), 96 deletions(-) (limited to 'include/linux') diff --git a/include/linux/mmu_notifier.h b/include/linux/mmu_notifier.h index a302925fbc61..4342fa75dc24 100644 --- a/include/linux/mmu_notifier.h +++ b/include/linux/mmu_notifier.h @@ -73,7 +73,7 @@ struct mmu_notifier_ops { * through the gart alias address, so leading to memory * corruption. */ - void (*release)(struct mmu_notifier *mn, + void (*release)(struct mmu_notifier *subscription, struct mm_struct *mm); /* @@ -85,7 +85,7 @@ struct mmu_notifier_ops { * Start-end is necessary in case the secondary MMU is mapping the page * at a smaller granularity than the primary MMU. */ - int (*clear_flush_young)(struct mmu_notifier *mn, + int (*clear_flush_young)(struct mmu_notifier *subscription, struct mm_struct *mm, unsigned long start, unsigned long end); @@ -95,7 +95,7 @@ struct mmu_notifier_ops { * latter, it is supposed to test-and-clear the young/accessed bitflag * in the secondary pte, but it may omit flushing the secondary tlb. */ - int (*clear_young)(struct mmu_notifier *mn, + int (*clear_young)(struct mmu_notifier *subscription, struct mm_struct *mm, unsigned long start, unsigned long end); @@ -106,7 +106,7 @@ struct mmu_notifier_ops { * frequently used without actually clearing the flag or tearing * down the secondary mapping on the page. */ - int (*test_young)(struct mmu_notifier *mn, + int (*test_young)(struct mmu_notifier *subscription, struct mm_struct *mm, unsigned long address); @@ -114,7 +114,7 @@ struct mmu_notifier_ops { * change_pte is called in cases that pte mapping to page is changed: * for example, when ksm remaps pte to point to a new shared page. */ - void (*change_pte)(struct mmu_notifier *mn, + void (*change_pte)(struct mmu_notifier *subscription, struct mm_struct *mm, unsigned long address, pte_t pte); @@ -169,9 +169,9 @@ struct mmu_notifier_ops { * invalidate_range_end. * */ - int (*invalidate_range_start)(struct mmu_notifier *mn, + int (*invalidate_range_start)(struct mmu_notifier *subscription, const struct mmu_notifier_range *range); - void (*invalidate_range_end)(struct mmu_notifier *mn, + void (*invalidate_range_end)(struct mmu_notifier *subscription, const struct mmu_notifier_range *range); /* @@ -192,8 +192,10 @@ struct mmu_notifier_ops { * of what was passed to invalidate_range_start()/end(), if * called between those functions. */ - void (*invalidate_range)(struct mmu_notifier *mn, struct mm_struct *mm, - unsigned long start, unsigned long end); + void (*invalidate_range)(struct mmu_notifier *subscription, + struct mm_struct *mm, + unsigned long start, + unsigned long end); /* * These callbacks are used with the get/put interface to manage the @@ -206,7 +208,7 @@ struct mmu_notifier_ops { * and cannot sleep. */ struct mmu_notifier *(*alloc_notifier)(struct mm_struct *mm); - void (*free_notifier)(struct mmu_notifier *mn); + void (*free_notifier)(struct mmu_notifier *subscription); }; /* @@ -280,14 +282,14 @@ mmu_notifier_get(const struct mmu_notifier_ops *ops, struct mm_struct *mm) up_write(&mm->mmap_sem); return ret; } -void mmu_notifier_put(struct mmu_notifier *mn); +void mmu_notifier_put(struct mmu_notifier *subscription); void mmu_notifier_synchronize(void); -extern int mmu_notifier_register(struct mmu_notifier *mn, +extern int mmu_notifier_register(struct mmu_notifier *subscription, struct mm_struct *mm); -extern int __mmu_notifier_register(struct mmu_notifier *mn, +extern int __mmu_notifier_register(struct mmu_notifier *subscription, struct mm_struct *mm); -extern void mmu_notifier_unregister(struct mmu_notifier *mn, +extern void mmu_notifier_unregister(struct mmu_notifier *subscription, struct mm_struct *mm); unsigned long mmu_interval_read_begin(struct mmu_interval_notifier *mni); diff --git a/mm/mmu_notifier.c b/mm/mmu_notifier.c index a409abfb9f26..12b35d8b444a 100644 --- a/mm/mmu_notifier.c +++ b/mm/mmu_notifier.c @@ -294,7 +294,7 @@ static void mn_itree_release(struct mmu_notifier_subscriptions *subscriptions, static void mn_hlist_release(struct mmu_notifier_subscriptions *subscriptions, struct mm_struct *mm) { - struct mmu_notifier *mn; + struct mmu_notifier *subscription; int id; /* @@ -302,27 +302,27 @@ static void mn_hlist_release(struct mmu_notifier_subscriptions *subscriptions, * ->release returns. */ id = srcu_read_lock(&srcu); - hlist_for_each_entry_rcu(mn, &subscriptions->list, hlist) + hlist_for_each_entry_rcu(subscription, &subscriptions->list, hlist) /* * If ->release runs before mmu_notifier_unregister it must be * handled, as it's the only way for the driver to flush all * existing sptes and stop the driver from establishing any more * sptes before all the pages in the mm are freed. */ - if (mn->ops->release) - mn->ops->release(mn, mm); + if (subscription->ops->release) + subscription->ops->release(subscription, mm); spin_lock(&subscriptions->lock); while (unlikely(!hlist_empty(&subscriptions->list))) { - mn = hlist_entry(subscriptions->list.first, struct mmu_notifier, - hlist); + subscription = hlist_entry(subscriptions->list.first, + struct mmu_notifier, hlist); /* * We arrived before mmu_notifier_unregister so * mmu_notifier_unregister will do nothing other than to wait * for ->release to finish and for mmu_notifier_unregister to * return. */ - hlist_del_init_rcu(&mn->hlist); + hlist_del_init_rcu(&subscription->hlist); } spin_unlock(&subscriptions->lock); srcu_read_unlock(&srcu, id); @@ -360,13 +360,15 @@ int __mmu_notifier_clear_flush_young(struct mm_struct *mm, unsigned long start, unsigned long end) { - struct mmu_notifier *mn; + struct mmu_notifier *subscription; int young = 0, id; id = srcu_read_lock(&srcu); - hlist_for_each_entry_rcu(mn, &mm->notifier_subscriptions->list, hlist) { - if (mn->ops->clear_flush_young) - young |= mn->ops->clear_flush_young(mn, mm, start, end); + hlist_for_each_entry_rcu(subscription, + &mm->notifier_subscriptions->list, hlist) { + if (subscription->ops->clear_flush_young) + young |= subscription->ops->clear_flush_young( + subscription, mm, start, end); } srcu_read_unlock(&srcu, id); @@ -377,13 +379,15 @@ int __mmu_notifier_clear_young(struct mm_struct *mm, unsigned long start, unsigned long end) { - struct mmu_notifier *mn; + struct mmu_notifier *subscription; int young = 0, id; id = srcu_read_lock(&srcu); - hlist_for_each_entry_rcu(mn, &mm->notifier_subscriptions->list, hlist) { - if (mn->ops->clear_young) - young |= mn->ops->clear_young(mn, mm, start, end); + hlist_for_each_entry_rcu(subscription, + &mm->notifier_subscriptions->list, hlist) { + if (subscription->ops->clear_young) + young |= subscription->ops->clear_young(subscription, + mm, start, end); } srcu_read_unlock(&srcu, id); @@ -393,13 +397,15 @@ int __mmu_notifier_clear_young(struct mm_struct *mm, int __mmu_notifier_test_young(struct mm_struct *mm, unsigned long address) { - struct mmu_notifier *mn; + struct mmu_notifier *subscription; int young = 0, id; id = srcu_read_lock(&srcu); - hlist_for_each_entry_rcu(mn, &mm->notifier_subscriptions->list, hlist) { - if (mn->ops->test_young) { - young = mn->ops->test_young(mn, mm, address); + hlist_for_each_entry_rcu(subscription, + &mm->notifier_subscriptions->list, hlist) { + if (subscription->ops->test_young) { + young = subscription->ops->test_young(subscription, mm, + address); if (young) break; } @@ -412,14 +418,15 @@ int __mmu_notifier_test_young(struct mm_struct *mm, void __mmu_notifier_change_pte(struct mm_struct *mm, unsigned long address, pte_t pte) { - struct mmu_notifier *mn; + struct mmu_notifier *subscription; int id; id = srcu_read_lock(&srcu); - hlist_for_each_entry_rcu(mn, &mm->notifier_subscriptions->list, - hlist) { - if (mn->ops->change_pte) - mn->ops->change_pte(mn, mm, address, pte); + hlist_for_each_entry_rcu(subscription, + &mm->notifier_subscriptions->list, hlist) { + if (subscription->ops->change_pte) + subscription->ops->change_pte(subscription, mm, address, + pte); } srcu_read_unlock(&srcu, id); } @@ -456,24 +463,28 @@ static int mn_hlist_invalidate_range_start( struct mmu_notifier_subscriptions *subscriptions, struct mmu_notifier_range *range) { - struct mmu_notifier *mn; + struct mmu_notifier *subscription; int ret = 0; int id; id = srcu_read_lock(&srcu); - hlist_for_each_entry_rcu(mn, &subscriptions->list, hlist) { - if (mn->ops->invalidate_range_start) { + hlist_for_each_entry_rcu(subscription, &subscriptions->list, hlist) { + const struct mmu_notifier_ops *ops = subscription->ops; + + if (ops->invalidate_range_start) { int _ret; if (!mmu_notifier_range_blockable(range)) non_block_start(); - _ret = mn->ops->invalidate_range_start(mn, range); + _ret = ops->invalidate_range_start(subscription, range); if (!mmu_notifier_range_blockable(range)) non_block_end(); if (_ret) { pr_info("%pS callback failed with %d in %sblockable context.\n", - mn->ops->invalidate_range_start, _ret, - !mmu_notifier_range_blockable(range) ? "non-" : ""); + ops->invalidate_range_start, _ret, + !mmu_notifier_range_blockable(range) ? + "non-" : + ""); WARN_ON(mmu_notifier_range_blockable(range) || _ret != -EAGAIN); ret = _ret; @@ -505,11 +516,11 @@ static void mn_hlist_invalidate_end(struct mmu_notifier_subscriptions *subscriptions, struct mmu_notifier_range *range, bool only_end) { - struct mmu_notifier *mn; + struct mmu_notifier *subscription; int id; id = srcu_read_lock(&srcu); - hlist_for_each_entry_rcu(mn, &subscriptions->list, hlist) { + hlist_for_each_entry_rcu(subscription, &subscriptions->list, hlist) { /* * Call invalidate_range here too to avoid the need for the * subsystem of having to register an invalidate_range_end @@ -523,14 +534,16 @@ mn_hlist_invalidate_end(struct mmu_notifier_subscriptions *subscriptions, * is safe to do when we know that a call to invalidate_range() * already happen under page table lock. */ - if (!only_end && mn->ops->invalidate_range) - mn->ops->invalidate_range(mn, range->mm, - range->start, - range->end); - if (mn->ops->invalidate_range_end) { + if (!only_end && subscription->ops->invalidate_range) + subscription->ops->invalidate_range(subscription, + range->mm, + range->start, + range->end); + if (subscription->ops->invalidate_range_end) { if (!mmu_notifier_range_blockable(range)) non_block_start(); - mn->ops->invalidate_range_end(mn, range); + subscription->ops->invalidate_range_end(subscription, + range); if (!mmu_notifier_range_blockable(range)) non_block_end(); } @@ -556,13 +569,15 @@ void __mmu_notifier_invalidate_range_end(struct mmu_notifier_range *range, void __mmu_notifier_invalidate_range(struct mm_struct *mm, unsigned long start, unsigned long end) { - struct mmu_notifier *mn; + struct mmu_notifier *subscription; int id; id = srcu_read_lock(&srcu); - hlist_for_each_entry_rcu(mn, &mm->notifier_subscriptions->list, hlist) { - if (mn->ops->invalidate_range) - mn->ops->invalidate_range(mn, mm, start, end); + hlist_for_each_entry_rcu(subscription, + &mm->notifier_subscriptions->list, hlist) { + if (subscription->ops->invalidate_range) + subscription->ops->invalidate_range(subscription, mm, + start, end); } srcu_read_unlock(&srcu, id); } @@ -572,7 +587,8 @@ void __mmu_notifier_invalidate_range(struct mm_struct *mm, * write mode. A NULL mn signals the notifier is being registered for itree * mode. */ -int __mmu_notifier_register(struct mmu_notifier *mn, struct mm_struct *mm) +int __mmu_notifier_register(struct mmu_notifier *subscription, + struct mm_struct *mm) { struct mmu_notifier_subscriptions *subscriptions = NULL; int ret; @@ -629,14 +645,14 @@ int __mmu_notifier_register(struct mmu_notifier *mn, struct mm_struct *mm) if (subscriptions) smp_store_release(&mm->notifier_subscriptions, subscriptions); - if (mn) { + if (subscription) { /* Pairs with the mmdrop in mmu_notifier_unregister_* */ mmgrab(mm); - mn->mm = mm; - mn->users = 1; + subscription->mm = mm; + subscription->users = 1; spin_lock(&mm->notifier_subscriptions->lock); - hlist_add_head_rcu(&mn->hlist, + hlist_add_head_rcu(&subscription->hlist, &mm->notifier_subscriptions->list); spin_unlock(&mm->notifier_subscriptions->lock); } else @@ -668,15 +684,16 @@ EXPORT_SYMBOL_GPL(__mmu_notifier_register); * mmu_notifier_unregister() or mmu_notifier_put() must be always called to * unregister the notifier. * - * While the caller has a mmu_notifier get the mn->mm pointer will remain + * While the caller has a mmu_notifier get the subscription->mm pointer will remain * valid, and can be converted to an active mm pointer via mmget_not_zero(). */ -int mmu_notifier_register(struct mmu_notifier *mn, struct mm_struct *mm) +int mmu_notifier_register(struct mmu_notifier *subscription, + struct mm_struct *mm) { int ret; down_write(&mm->mmap_sem); - ret = __mmu_notifier_register(mn, mm); + ret = __mmu_notifier_register(subscription, mm); up_write(&mm->mmap_sem); return ret; } @@ -685,20 +702,20 @@ EXPORT_SYMBOL_GPL(mmu_notifier_register); static struct mmu_notifier * find_get_mmu_notifier(struct mm_struct *mm, const struct mmu_notifier_ops *ops) { - struct mmu_notifier *mn; + struct mmu_notifier *subscription; spin_lock(&mm->notifier_subscriptions->lock); - hlist_for_each_entry_rcu(mn, &mm->notifier_subscriptions->list, - hlist) { - if (mn->ops != ops) + hlist_for_each_entry_rcu(subscription, + &mm->notifier_subscriptions->list, hlist) { + if (subscription->ops != ops) continue; - if (likely(mn->users != UINT_MAX)) - mn->users++; + if (likely(subscription->users != UINT_MAX)) + subscription->users++; else - mn = ERR_PTR(-EOVERFLOW); + subscription = ERR_PTR(-EOVERFLOW); spin_unlock(&mm->notifier_subscriptions->lock); - return mn; + return subscription; } spin_unlock(&mm->notifier_subscriptions->lock); return NULL; @@ -724,27 +741,27 @@ find_get_mmu_notifier(struct mm_struct *mm, const struct mmu_notifier_ops *ops) struct mmu_notifier *mmu_notifier_get_locked(const struct mmu_notifier_ops *ops, struct mm_struct *mm) { - struct mmu_notifier *mn; + struct mmu_notifier *subscription; int ret; lockdep_assert_held_write(&mm->mmap_sem); if (mm->notifier_subscriptions) { - mn = find_get_mmu_notifier(mm, ops); - if (mn) - return mn; + subscription = find_get_mmu_notifier(mm, ops); + if (subscription) + return subscription; } - mn = ops->alloc_notifier(mm); - if (IS_ERR(mn)) - return mn; - mn->ops = ops; - ret = __mmu_notifier_register(mn, mm); + subscription = ops->alloc_notifier(mm); + if (IS_ERR(subscription)) + return subscription; + subscription->ops = ops; + ret = __mmu_notifier_register(subscription, mm); if (ret) goto out_free; - return mn; + return subscription; out_free: - mn->ops->free_notifier(mn); + subscription->ops->free_notifier(subscription); return ERR_PTR(ret); } EXPORT_SYMBOL_GPL(mmu_notifier_get_locked); @@ -767,11 +784,12 @@ void __mmu_notifier_subscriptions_destroy(struct mm_struct *mm) * and only after mmu_notifier_unregister returned we're guaranteed * that ->release or any other method can't run anymore. */ -void mmu_notifier_unregister(struct mmu_notifier *mn, struct mm_struct *mm) +void mmu_notifier_unregister(struct mmu_notifier *subscription, + struct mm_struct *mm) { BUG_ON(atomic_read(&mm->mm_count) <= 0); - if (!hlist_unhashed(&mn->hlist)) { + if (!hlist_unhashed(&subscription->hlist)) { /* * SRCU here will force exit_mmap to wait for ->release to * finish before freeing the pages. @@ -783,8 +801,8 @@ void mmu_notifier_unregister(struct mmu_notifier *mn, struct mm_struct *mm) * exit_mmap will block in mmu_notifier_release to guarantee * that ->release is called before freeing the pages. */ - if (mn->ops->release) - mn->ops->release(mn, mm); + if (subscription->ops->release) + subscription->ops->release(subscription, mm); srcu_read_unlock(&srcu, id); spin_lock(&mm->notifier_subscriptions->lock); @@ -792,7 +810,7 @@ void mmu_notifier_unregister(struct mmu_notifier *mn, struct mm_struct *mm) * Can not use list_del_rcu() since __mmu_notifier_release * can delete it before we hold the lock. */ - hlist_del_init_rcu(&mn->hlist); + hlist_del_init_rcu(&subscription->hlist); spin_unlock(&mm->notifier_subscriptions->lock); } @@ -810,10 +828,11 @@ EXPORT_SYMBOL_GPL(mmu_notifier_unregister); static void mmu_notifier_free_rcu(struct rcu_head *rcu) { - struct mmu_notifier *mn = container_of(rcu, struct mmu_notifier, rcu); - struct mm_struct *mm = mn->mm; + struct mmu_notifier *subscription = + container_of(rcu, struct mmu_notifier, rcu); + struct mm_struct *mm = subscription->mm; - mn->ops->free_notifier(mn); + subscription->ops->free_notifier(subscription); /* Pairs with the get in __mmu_notifier_register() */ mmdrop(mm); } @@ -840,17 +859,17 @@ static void mmu_notifier_free_rcu(struct rcu_head *rcu) * Modules calling this function must call mmu_notifier_synchronize() in * their __exit functions to ensure the async work is completed. */ -void mmu_notifier_put(struct mmu_notifier *mn) +void mmu_notifier_put(struct mmu_notifier *subscription) { - struct mm_struct *mm = mn->mm; + struct mm_struct *mm = subscription->mm; spin_lock(&mm->notifier_subscriptions->lock); - if (WARN_ON(!mn->users) || --mn->users) + if (WARN_ON(!subscription->users) || --subscription->users) goto out_unlock; - hlist_del_init_rcu(&mn->hlist); + hlist_del_init_rcu(&subscription->hlist); spin_unlock(&mm->notifier_subscriptions->lock); - call_srcu(&srcu, &mn->rcu, mmu_notifier_free_rcu); + call_srcu(&srcu, &subscription->rcu, mmu_notifier_free_rcu); return; out_unlock: -- cgit v1.2.3-71-gd317 From 5292e24a6acf5694e0a32c31e3321964176bc17e Mon Sep 17 00:00:00 2001 From: Jason Gunthorpe Date: Tue, 14 Jan 2020 11:29:52 -0400 Subject: mm/mmu_notifiers: Use 'interval_sub' as the variable for mmu_interval_notifier The 'interval_sub' is placed on the 'notifier_subscriptions' interval tree. This eliminates the poor name 'mni' for this variable. Signed-off-by: Jason Gunthorpe --- Documentation/vm/hmm.rst | 20 +++---- include/linux/mmu_notifier.h | 38 ++++++------ mm/mmu_notifier.c | 136 +++++++++++++++++++++++-------------------- 3 files changed, 104 insertions(+), 90 deletions(-) (limited to 'include/linux') diff --git a/Documentation/vm/hmm.rst b/Documentation/vm/hmm.rst index 893a8ba0e9fe..95fec5968362 100644 --- a/Documentation/vm/hmm.rst +++ b/Documentation/vm/hmm.rst @@ -149,14 +149,14 @@ CPU page table into a device page table; HMM helps keep both synchronized. A device driver that wants to mirror a process address space must start with the registration of a mmu_interval_notifier:: - mni->ops = &driver_ops; - int mmu_interval_notifier_insert(struct mmu_interval_notifier *mni, - unsigned long start, unsigned long length, - struct mm_struct *mm); + int mmu_interval_notifier_insert(struct mmu_interval_notifier *interval_sub, + struct mm_struct *mm, unsigned long start, + unsigned long length, + const struct mmu_interval_notifier_ops *ops); -During the driver_ops->invalidate() callback the device driver must perform -the update action to the range (mark range read only, or fully unmap, -etc.). The device must complete the update before the driver callback returns. +During the ops->invalidate() callback the device driver must perform the +update action to the range (mark range read only, or fully unmap, etc.). The +device must complete the update before the driver callback returns. When the device driver wants to populate a range of virtual addresses, it can use:: @@ -183,7 +183,7 @@ The usage pattern is:: struct hmm_range range; ... - range.notifier = &mni; + range.notifier = &interval_sub; range.start = ...; range.end = ...; range.pfns = ...; @@ -191,11 +191,11 @@ The usage pattern is:: range.values = ...; range.pfn_shift = ...; - if (!mmget_not_zero(mni->notifier.mm)) + if (!mmget_not_zero(interval_sub->notifier.mm)) return -EFAULT; again: - range.notifier_seq = mmu_interval_read_begin(&mni); + range.notifier_seq = mmu_interval_read_begin(&interval_sub); down_read(&mm->mmap_sem); ret = hmm_range_fault(&range, HMM_RANGE_SNAPSHOT); if (ret) { diff --git a/include/linux/mmu_notifier.h b/include/linux/mmu_notifier.h index 4342fa75dc24..736f6918335e 100644 --- a/include/linux/mmu_notifier.h +++ b/include/linux/mmu_notifier.h @@ -237,7 +237,7 @@ struct mmu_notifier { * was required but mmu_notifier_range_blockable(range) is false. */ struct mmu_interval_notifier_ops { - bool (*invalidate)(struct mmu_interval_notifier *mni, + bool (*invalidate)(struct mmu_interval_notifier *interval_sub, const struct mmu_notifier_range *range, unsigned long cur_seq); }; @@ -292,20 +292,21 @@ extern int __mmu_notifier_register(struct mmu_notifier *subscription, extern void mmu_notifier_unregister(struct mmu_notifier *subscription, struct mm_struct *mm); -unsigned long mmu_interval_read_begin(struct mmu_interval_notifier *mni); -int mmu_interval_notifier_insert(struct mmu_interval_notifier *mni, +unsigned long +mmu_interval_read_begin(struct mmu_interval_notifier *interval_sub); +int mmu_interval_notifier_insert(struct mmu_interval_notifier *interval_sub, struct mm_struct *mm, unsigned long start, unsigned long length, const struct mmu_interval_notifier_ops *ops); int mmu_interval_notifier_insert_locked( - struct mmu_interval_notifier *mni, struct mm_struct *mm, + struct mmu_interval_notifier *interval_sub, struct mm_struct *mm, unsigned long start, unsigned long length, const struct mmu_interval_notifier_ops *ops); -void mmu_interval_notifier_remove(struct mmu_interval_notifier *mni); +void mmu_interval_notifier_remove(struct mmu_interval_notifier *interval_sub); /** * mmu_interval_set_seq - Save the invalidation sequence - * @mni - The mni passed to invalidate + * @interval_sub - The subscription passed to invalidate * @cur_seq - The cur_seq passed to the invalidate() callback * * This must be called unconditionally from the invalidate callback of a @@ -316,15 +317,16 @@ void mmu_interval_notifier_remove(struct mmu_interval_notifier *mni); * If the caller does not call mmu_interval_read_begin() or * mmu_interval_read_retry() then this call is not required. */ -static inline void mmu_interval_set_seq(struct mmu_interval_notifier *mni, - unsigned long cur_seq) +static inline void +mmu_interval_set_seq(struct mmu_interval_notifier *interval_sub, + unsigned long cur_seq) { - WRITE_ONCE(mni->invalidate_seq, cur_seq); + WRITE_ONCE(interval_sub->invalidate_seq, cur_seq); } /** * mmu_interval_read_retry - End a read side critical section against a VA range - * mni: The range + * interval_sub: The subscription * seq: The return of the paired mmu_interval_read_begin() * * This MUST be called under a user provided lock that is also held @@ -336,15 +338,16 @@ static inline void mmu_interval_set_seq(struct mmu_interval_notifier *mni, * Returns true if an invalidation collided with this critical section, and * the caller should retry. */ -static inline bool mmu_interval_read_retry(struct mmu_interval_notifier *mni, - unsigned long seq) +static inline bool +mmu_interval_read_retry(struct mmu_interval_notifier *interval_sub, + unsigned long seq) { - return mni->invalidate_seq != seq; + return interval_sub->invalidate_seq != seq; } /** * mmu_interval_check_retry - Test if a collision has occurred - * mni: The range + * interval_sub: The subscription * seq: The return of the matching mmu_interval_read_begin() * * This can be used in the critical section between mmu_interval_read_begin() @@ -359,11 +362,12 @@ static inline bool mmu_interval_read_retry(struct mmu_interval_notifier *mni, * This call can be used as part of loops and other expensive operations to * expedite a retry. */ -static inline bool mmu_interval_check_retry(struct mmu_interval_notifier *mni, - unsigned long seq) +static inline bool +mmu_interval_check_retry(struct mmu_interval_notifier *interval_sub, + unsigned long seq) { /* Pairs with the WRITE_ONCE in mmu_interval_set_seq() */ - return READ_ONCE(mni->invalidate_seq) != seq; + return READ_ONCE(interval_sub->invalidate_seq) != seq; } extern void __mmu_notifier_subscriptions_destroy(struct mm_struct *mm); diff --git a/mm/mmu_notifier.c b/mm/mmu_notifier.c index 12b35d8b444a..ef3973a5d34a 100644 --- a/mm/mmu_notifier.c +++ b/mm/mmu_notifier.c @@ -81,7 +81,7 @@ struct mmu_notifier_subscriptions { * seq & 1 # True if a writer exists * * The later state avoids some expensive work on inv_end in the common case of - * no mni monitoring the VA. + * no mmu_interval_notifier monitoring the VA. */ static bool mn_itree_is_invalidating(struct mmu_notifier_subscriptions *subscriptions) @@ -114,13 +114,13 @@ mn_itree_inv_start_range(struct mmu_notifier_subscriptions *subscriptions, } static struct mmu_interval_notifier * -mn_itree_inv_next(struct mmu_interval_notifier *mni, +mn_itree_inv_next(struct mmu_interval_notifier *interval_sub, const struct mmu_notifier_range *range) { struct interval_tree_node *node; - node = interval_tree_iter_next(&mni->interval_tree, range->start, - range->end - 1); + node = interval_tree_iter_next(&interval_sub->interval_tree, + range->start, range->end - 1); if (!node) return NULL; return container_of(node, struct mmu_interval_notifier, interval_tree); @@ -128,7 +128,7 @@ mn_itree_inv_next(struct mmu_interval_notifier *mni, static void mn_itree_inv_end(struct mmu_notifier_subscriptions *subscriptions) { - struct mmu_interval_notifier *mni; + struct mmu_interval_notifier *interval_sub; struct hlist_node *next; spin_lock(&subscriptions->lock); @@ -147,15 +147,16 @@ static void mn_itree_inv_end(struct mmu_notifier_subscriptions *subscriptions) * they are progressed. This arrangement for tree updates is used to * avoid using a blocking lock during invalidate_range_start. */ - hlist_for_each_entry_safe(mni, next, &subscriptions->deferred_list, + hlist_for_each_entry_safe(interval_sub, next, + &subscriptions->deferred_list, deferred_item) { - if (RB_EMPTY_NODE(&mni->interval_tree.rb)) - interval_tree_insert(&mni->interval_tree, + if (RB_EMPTY_NODE(&interval_sub->interval_tree.rb)) + interval_tree_insert(&interval_sub->interval_tree, &subscriptions->itree); else - interval_tree_remove(&mni->interval_tree, + interval_tree_remove(&interval_sub->interval_tree, &subscriptions->itree); - hlist_del(&mni->deferred_item); + hlist_del(&interval_sub->deferred_item); } spin_unlock(&subscriptions->lock); @@ -165,12 +166,12 @@ static void mn_itree_inv_end(struct mmu_notifier_subscriptions *subscriptions) /** * mmu_interval_read_begin - Begin a read side critical section against a VA * range - * mni: The range to use + * interval_sub: The interval subscription * * mmu_iterval_read_begin()/mmu_iterval_read_retry() implement a - * collision-retry scheme similar to seqcount for the VA range under mni. If - * the mm invokes invalidation during the critical section then - * mmu_interval_read_retry() will return true. + * collision-retry scheme similar to seqcount for the VA range under + * subscription. If the mm invokes invalidation during the critical section + * then mmu_interval_read_retry() will return true. * * This is useful to obtain shadow PTEs where teardown or setup of the SPTEs * require a blocking context. The critical region formed by this can sleep, @@ -181,25 +182,26 @@ static void mn_itree_inv_end(struct mmu_notifier_subscriptions *subscriptions) * * The return value should be passed to mmu_interval_read_retry(). */ -unsigned long mmu_interval_read_begin(struct mmu_interval_notifier *mni) +unsigned long +mmu_interval_read_begin(struct mmu_interval_notifier *interval_sub) { struct mmu_notifier_subscriptions *subscriptions = - mni->mm->notifier_subscriptions; + interval_sub->mm->notifier_subscriptions; unsigned long seq; bool is_invalidating; /* - * If the mni has a different seq value under the user_lock than we - * started with then it has collided. + * If the subscription has a different seq value under the user_lock + * than we started with then it has collided. * - * If the mni currently has the same seq value as the subscriptions - * seq, then it is currently between invalidate_start/end and is - * colliding. + * If the subscription currently has the same seq value as the + * subscriptions seq, then it is currently between + * invalidate_start/end and is colliding. * * The locking looks broadly like this: * mn_tree_invalidate_start(): mmu_interval_read_begin(): * spin_lock - * seq = READ_ONCE(mni->invalidate_seq); + * seq = READ_ONCE(interval_sub->invalidate_seq); * seq == subs->invalidate_seq * spin_unlock * spin_lock @@ -208,7 +210,7 @@ unsigned long mmu_interval_read_begin(struct mmu_interval_notifier *mni) * op->invalidate_range(): * user_lock * mmu_interval_set_seq() - * mni->invalidate_seq = seq + * interval_sub->invalidate_seq = seq * user_unlock * * [Required: mmu_interval_read_retry() == true] @@ -220,7 +222,7 @@ unsigned long mmu_interval_read_begin(struct mmu_interval_notifier *mni) * * user_lock * mmu_interval_read_retry(): - * mni->invalidate_seq != seq + * interval_sub->invalidate_seq != seq * user_unlock * * Barriers are not needed here as any races here are closed by an @@ -229,12 +231,12 @@ unsigned long mmu_interval_read_begin(struct mmu_interval_notifier *mni) */ spin_lock(&subscriptions->lock); /* Pairs with the WRITE_ONCE in mmu_interval_set_seq() */ - seq = READ_ONCE(mni->invalidate_seq); + seq = READ_ONCE(interval_sub->invalidate_seq); is_invalidating = seq == subscriptions->invalidate_seq; spin_unlock(&subscriptions->lock); /* - * mni->invalidate_seq must always be set to an odd value via + * interval_sub->invalidate_seq must always be set to an odd value via * mmu_interval_set_seq() using the provided cur_seq from * mn_itree_inv_start_range(). This ensures that if seq does wrap we * will always clear the below sleep in some reasonable time as @@ -266,13 +268,16 @@ static void mn_itree_release(struct mmu_notifier_subscriptions *subscriptions, .start = 0, .end = ULONG_MAX, }; - struct mmu_interval_notifier *mni; + struct mmu_interval_notifier *interval_sub; unsigned long cur_seq; bool ret; - for (mni = mn_itree_inv_start_range(subscriptions, &range, &cur_seq); - mni; mni = mn_itree_inv_next(mni, &range)) { - ret = mni->ops->invalidate(mni, &range, cur_seq); + for (interval_sub = + mn_itree_inv_start_range(subscriptions, &range, &cur_seq); + interval_sub; + interval_sub = mn_itree_inv_next(interval_sub, &range)) { + ret = interval_sub->ops->invalidate(interval_sub, &range, + cur_seq); WARN_ON(!ret); } @@ -434,14 +439,17 @@ void __mmu_notifier_change_pte(struct mm_struct *mm, unsigned long address, static int mn_itree_invalidate(struct mmu_notifier_subscriptions *subscriptions, const struct mmu_notifier_range *range) { - struct mmu_interval_notifier *mni; + struct mmu_interval_notifier *interval_sub; unsigned long cur_seq; - for (mni = mn_itree_inv_start_range(subscriptions, range, &cur_seq); - mni; mni = mn_itree_inv_next(mni, range)) { + for (interval_sub = + mn_itree_inv_start_range(subscriptions, range, &cur_seq); + interval_sub; + interval_sub = mn_itree_inv_next(interval_sub, range)) { bool ret; - ret = mni->ops->invalidate(mni, range, cur_seq); + ret = interval_sub->ops->invalidate(interval_sub, range, + cur_seq); if (!ret) { if (WARN_ON(mmu_notifier_range_blockable(range))) continue; @@ -878,20 +886,21 @@ out_unlock: EXPORT_SYMBOL_GPL(mmu_notifier_put); static int __mmu_interval_notifier_insert( - struct mmu_interval_notifier *mni, struct mm_struct *mm, + struct mmu_interval_notifier *interval_sub, struct mm_struct *mm, struct mmu_notifier_subscriptions *subscriptions, unsigned long start, unsigned long length, const struct mmu_interval_notifier_ops *ops) { - mni->mm = mm; - mni->ops = ops; - RB_CLEAR_NODE(&mni->interval_tree.rb); - mni->interval_tree.start = start; + interval_sub->mm = mm; + interval_sub->ops = ops; + RB_CLEAR_NODE(&interval_sub->interval_tree.rb); + interval_sub->interval_tree.start = start; /* * Note that the representation of the intervals in the interval tree * considers the ending point as contained in the interval. */ if (length == 0 || - check_add_overflow(start, length - 1, &mni->interval_tree.last)) + check_add_overflow(start, length - 1, + &interval_sub->interval_tree.last)) return -EOVERFLOW; /* Must call with a mmget() held */ @@ -911,30 +920,31 @@ static int __mmu_interval_notifier_insert( * possibility for live lock, instead defer the add to * mn_itree_inv_end() so this algorithm is deterministic. * - * In all cases the value for the mni->invalidate_seq should be + * In all cases the value for the interval_sub->invalidate_seq should be * odd, see mmu_interval_read_begin() */ spin_lock(&subscriptions->lock); if (subscriptions->active_invalidate_ranges) { if (mn_itree_is_invalidating(subscriptions)) - hlist_add_head(&mni->deferred_item, + hlist_add_head(&interval_sub->deferred_item, &subscriptions->deferred_list); else { subscriptions->invalidate_seq |= 1; - interval_tree_insert(&mni->interval_tree, + interval_tree_insert(&interval_sub->interval_tree, &subscriptions->itree); } - mni->invalidate_seq = subscriptions->invalidate_seq; + interval_sub->invalidate_seq = subscriptions->invalidate_seq; } else { WARN_ON(mn_itree_is_invalidating(subscriptions)); /* - * The starting seq for a mni not under invalidation should be - * odd, not equal to the current invalidate_seq and + * The starting seq for a subscription not under invalidation + * should be odd, not equal to the current invalidate_seq and * invalidate_seq should not 'wrap' to the new seq any time * soon. */ - mni->invalidate_seq = subscriptions->invalidate_seq - 1; - interval_tree_insert(&mni->interval_tree, + interval_sub->invalidate_seq = + subscriptions->invalidate_seq - 1; + interval_tree_insert(&interval_sub->interval_tree, &subscriptions->itree); } spin_unlock(&subscriptions->lock); @@ -943,7 +953,7 @@ static int __mmu_interval_notifier_insert( /** * mmu_interval_notifier_insert - Insert an interval notifier - * @mni: Interval notifier to register + * @interval_sub: Interval subscription to register * @start: Starting virtual address to monitor * @length: Length of the range to monitor * @mm : mm_struct to attach to @@ -956,7 +966,7 @@ static int __mmu_interval_notifier_insert( * The caller must use the normal interval notifier read flow via * mmu_interval_read_begin() to establish SPTEs for this range. */ -int mmu_interval_notifier_insert(struct mmu_interval_notifier *mni, +int mmu_interval_notifier_insert(struct mmu_interval_notifier *interval_sub, struct mm_struct *mm, unsigned long start, unsigned long length, const struct mmu_interval_notifier_ops *ops) @@ -973,13 +983,13 @@ int mmu_interval_notifier_insert(struct mmu_interval_notifier *mni, return ret; subscriptions = mm->notifier_subscriptions; } - return __mmu_interval_notifier_insert(mni, mm, subscriptions, start, - length, ops); + return __mmu_interval_notifier_insert(interval_sub, mm, subscriptions, + start, length, ops); } EXPORT_SYMBOL_GPL(mmu_interval_notifier_insert); int mmu_interval_notifier_insert_locked( - struct mmu_interval_notifier *mni, struct mm_struct *mm, + struct mmu_interval_notifier *interval_sub, struct mm_struct *mm, unsigned long start, unsigned long length, const struct mmu_interval_notifier_ops *ops) { @@ -995,14 +1005,14 @@ int mmu_interval_notifier_insert_locked( return ret; subscriptions = mm->notifier_subscriptions; } - return __mmu_interval_notifier_insert(mni, mm, subscriptions, start, - length, ops); + return __mmu_interval_notifier_insert(interval_sub, mm, subscriptions, + start, length, ops); } EXPORT_SYMBOL_GPL(mmu_interval_notifier_insert_locked); /** * mmu_interval_notifier_remove - Remove a interval notifier - * @mni: Interval notifier to unregister + * @interval_sub: Interval subscription to unregister * * This function must be paired with mmu_interval_notifier_insert(). It cannot * be called from any ops callback. @@ -1010,9 +1020,9 @@ EXPORT_SYMBOL_GPL(mmu_interval_notifier_insert_locked); * Once this returns ops callbacks are no longer running on other CPUs and * will not be called in future. */ -void mmu_interval_notifier_remove(struct mmu_interval_notifier *mni) +void mmu_interval_notifier_remove(struct mmu_interval_notifier *interval_sub) { - struct mm_struct *mm = mni->mm; + struct mm_struct *mm = interval_sub->mm; struct mmu_notifier_subscriptions *subscriptions = mm->notifier_subscriptions; unsigned long seq = 0; @@ -1025,16 +1035,16 @@ void mmu_interval_notifier_remove(struct mmu_interval_notifier *mni) * remove is being called after insert put this on the * deferred list, but before the deferred list was processed. */ - if (RB_EMPTY_NODE(&mni->interval_tree.rb)) { - hlist_del(&mni->deferred_item); + if (RB_EMPTY_NODE(&interval_sub->interval_tree.rb)) { + hlist_del(&interval_sub->deferred_item); } else { - hlist_add_head(&mni->deferred_item, + hlist_add_head(&interval_sub->deferred_item, &subscriptions->deferred_list); seq = subscriptions->invalidate_seq; } } else { - WARN_ON(RB_EMPTY_NODE(&mni->interval_tree.rb)); - interval_tree_remove(&mni->interval_tree, + WARN_ON(RB_EMPTY_NODE(&interval_sub->interval_tree.rb)); + interval_tree_remove(&interval_sub->interval_tree, &subscriptions->itree); } spin_unlock(&subscriptions->lock); -- cgit v1.2.3-71-gd317